portemento, adsr

Source/shifter_voice.cpp

@@ -0,0 +1,91 @@
+/*
+  ==============================================================================
+
+	shifter_voice.cpp
+	Created: 25 Oct 2025 2:09:42pm
+	Author:  mickl
+
+  ==============================================================================
+*/
+
+#include "shifter_voice.h"
+
+
+static inline float mtof(float m)
+{
+	return powf(2, (m - 69.0f) / 12.0f) * 440.0f;
+}
+
+
+void ShifterVoice::Init(float sample_rate) {
+	portamento_.Init(sample_rate, 0.05f); //default portamento time
+	amplitude_envelope_.Init(sample_rate);
+	amplitude_envelope_.SetAttackTime(0.2f);
+	amplitude_envelope_.SetDecayTime(0.2f);	
+	amplitude_envelope_.SetReleaseTime(1.0f);
+	onoff_ = false;
+	overflow_ = false;
+	current_midi = 60;
+	current_period_ = 48000.0f / mtof((float)current_midi);
+	current_amplitude = 0.0f;
+	period_counter = 0.0f;
+	panning = 0.5f;
+}
+
+
+bool ShifterVoice::IsActive() { return amplitude_envelope_.IsRunning(); }
+
+void ShifterVoice::Trigger(int midi_note) {
+	current_midi = midi_note;
+	// Retrigger envelope
+	amplitude_envelope_.Retrigger(false);
+	onoff_ = true;
+	panning = rand() / (float)RAND_MAX;
+}
+
+void ShifterVoice::Release() {
+	onoff_ = false;
+}
+
+void ShifterVoice::Process() {
+	current_amplitude = amplitude_envelope_.Process(onoff_);
+	current_period_ = 48000.0f / mtof(portamento_.Process((float)current_midi));
+	period_counter++;
+	overflow_ = period_counter >= current_period_;
+	if (overflow_) {
+		period_counter -= current_period_;
+	}
+}
+
+float ShifterVoice::CurrentAmplitude() {
+	return current_amplitude;
+}
+
+float ShifterVoice::CurrentPeriod() {
+	return current_period_;
+}
+
+bool ShifterVoice::PeriodOverflow() {
+	return overflow_;
+}
+
+void ShifterVoice::SetPortamentoTime(float time) {
+	portamento_.SetHtime(time);
+}
+
+void ShifterVoice::SetAdsrTimes(float attack, float decay, float release) {
+	amplitude_envelope_.SetAttackTime(attack);
+	amplitude_envelope_.SetDecayTime(decay);
+	amplitude_envelope_.SetReleaseTime(release);
+	amplitude_envelope_.SetSustainLevel(1.0);
+}
+
+float ShifterVoice::GetPanning(int channel) const {
+	switch (channel) {
+	default:
+	case 0:
+		return panning < .5 ? 1.0 : 2.0f - (panning * 2.0f);
+	case 1:
+		return panning > .5 ? 1.0 : panning * 2.0f;
+	}
+}